Re: [RFC PATCH v4 00/19] Core scheduling v4

[Li, Aubrey]

On 2019/11/1 19:33, Li, Aubrey wrote:
> On 2019/10/31 19:42, Li, Aubrey wrote:
>> On 2019/10/31 2:33, Vineeth Remanan Pillai wrote:
>>> Fourth iteration of the Core-Scheduling feature.
>>>
>>> This version was aiming mostly at addressing the vruntime comparison
>>> issues with v3. The main issue seen in v3 was the starvation of
>>> interactive tasks when competing with cpu intensive tasks. This issue
>>> is mitigated to a large extent.
>>>
>>> We have tested and verified that incompatible processes are not
>>> selected during schedule. In terms of performance, the impact
>>> depends on the workload:
>>> - on CPU intensive applications that use all the logical CPUs with
>>>   SMT enabled, enabling core scheduling performs better than nosmt.
>>> - on mixed workloads with considerable io compared to cpu usage,
>>>   nosmt seems to perform better than core scheduling.
>>>
>>> v4 is rebased on top of 5.3.5(dc073f193b70):
>>> https://github.com/digitalocean/linux-coresched/tree/coresched/v4-v5.3.5
>>
>> Thanks to post V4 out. Refresh the data on my side. Since we have played
>> with Aaron's core vruntime patch for a while, no surprise in the result.
>>
> I have three small patches against V4. The basic idea is,
> - for load balance, don't pull/push task if its cookie does not match with
> destination CPU's core cookie
> - for task wakeup, select idle CPU whose core cookie matches with task's
> cookie.
> 
> Sysbench MySQL result shows significant improvement for the overload cases.
>
> This may be the workload specific. Looking forward to more testing and comments.
> 

Here is another one for task numa migration. We saw significant latency
improvement of workload sysbench MYSQL+gemmbench, for the overloaded case
on a 8-node system, the latency is reduced from 93.78ms to 28.36ms. So I
think it's worth to post this twist to draw more ideas and better solutions.

Thanks,
-Aubrey

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